JAMA's study on B vitamins lacks criteria and controls, says NPA

NPA Staff | Jul 21, 2008

The study results do not apply to a healthy population.

Opinion by the Natural Products Association — JAMA, the Journal of the American Medical Association, is releasing a report on a clinical trial that concluded that use of B vitamins was not effective for preventing death or cardiovascular events. The study will appear in the August 20 issue of the journal. In response to the findings, the Natural Products Association issued the following statement from Vice President of Scientific and Regulatory Affairs Daniel Fabricant, Ph.D.:

"The study's exclusion criteria leave much to be desired. For example, over 78 percent of the subjects were concomitantly taking beta blockers, and over 88 percent were taking statins amongst other medical interventions and treatments. We have no way of knowing from reading the study whether these interventions were continued through the lifecycle of the study, which could significantly influence the outcomes. The researchers mention adherence to the 'study medication' (the B-vitamins) but not to other treatments; additionally the authors did not control food intake for folic acid, B-6 or B-12. They simply dismiss this factor by saying that fortified foods aren't 'required' in Norway. Does that mean fortified foods are not available or being consumed in Norway? The study authors also claim that self-reported use of B-vitamins was low. Did the researchers actually have the subjects bring in the supplements they were taking to accurately analyze this? Of course not. All of these variables have the ability to influence the outcome and needed to be controlled for.

"Researchers realize there is debate over homocysteine (hcy) level as a marker for existing cardiovascular disease (CVD) or a predictor of CVD. Randomized clinical trials are currently testing whether lowering hcy levels through supplementation with B vitamins will reduce CVD. However, what we know for certain is that there are significant populations of older people with CVD who have moderately low concentrations of serum vitamin B12; similarly, there are also populations of the elderly with CVD that have elevated concentrations of plasma hcy. Applying some degree of common sense, there is a plausible link that needs to be investigated further. It is important, however that these findings not become generalized, applied and reported to be related to a healthy population that may be responsibly supplementing with B vitamins and the preventative benefits they may derive.

"A study such as this one from JAMA, which does not properly control the variables needed to acquire more knowledge regarding the potential links between b-vitamins, HCY levels and CVD, is in no way conclusiveand should not represented as such, or be used in any way to stop those who may currently benefit from taking B-vitamins from continuing their regimens. The overwhelming body of research shows that poor nutrition is much more of a health risk than using optimal levels of B-vitamin supplementation in a balanced diet, exercise and health regimen."